Aptitude - Probability

Why should I learn to solve Aptitude questions and answers section on "Probability"?

Learn and practise solving Aptitude questions and answers section on "Probability" to enhance your skills so that you can clear interviews, competitive examinations, and various entrance tests (CAT, GATE, GRE, MAT, bank exams, railway exams, etc.) with full confidence.

Where can I get the Aptitude questions and answers section on "Probability"?

IndiaBIX provides you with numerous Aptitude questions and answers based on "Probability" along with fully solved examples and detailed explanations that will be easy to understand.

Where can I get the Aptitude section on "Probability" MCQ-type interview questions and answers (objective type, multiple choice)?

Here you can find multiple-choice Aptitude questions and answers based on "Probability" for your placement interviews and competitive exams. Objective-type and true-or-false-type questions are given too.

How do I download the Aptitude questions and answers section on "Probability" in PDF format?

You can download the Aptitude quiz questions and answers section on "Probability" as PDF files or eBooks.

How do I solve Aptitude quiz problems based on "Probability"?

You can easily solve Aptitude quiz problems based on "Probability" by practising the given exercises, including shortcuts and tricks.

Exercise : Probability - General Questions
1.
Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn has a number which is a multiple of 3 or 5?
1
2
2
5
8
15
9
20
Answer: Option
Explanation:

Here, S = {1, 2, 3, 4, ...., 19, 20}.

Let E = event of getting a multiple of 3 or 5 = {3, 6 , 9, 12, 15, 18, 5, 10, 20}.

P(E) = n(E) = 9 .
n(S) 20


2.
A bag contains 2 red, 3 green and 2 blue balls. Two balls are drawn at random. What is the probability that none of the balls drawn is blue?
10
21
11
21
2
7
5
7
Answer: Option
Explanation:

Total number of balls = (2 + 3 + 2) = 7.

Let S be the sample space.

Then, n(S) = Number of ways of drawing 2 balls out of 7
= 7C2 `
= (7 x 6)
(2 x 1)
= 21.

Let E = Event of drawing 2 balls, none of which is blue.

n(E) = Number of ways of drawing 2 balls out of (2 + 3) balls.
= 5C2
= (5 x 4)
(2 x 1)
= 10.

P(E) = n(E) = 10 .
n(S) 21


3.
In a box, there are 8 red, 7 blue and 6 green balls. One ball is picked up randomly. What is the probability that it is neither red nor green?
1
3
3
4
7
19
8
21
9
21
Answer: Option
Explanation:

Total number of balls = (8 + 7 + 6) = 21.

Let E = event that the ball drawn is neither red nor green
= event that the ball drawn is blue.

n(E) = 7.

P(E) = n(E) = 7 = 1 .
n(S) 21 3


4.
What is the probability of getting a sum 9 from two throws of a dice?
1
6
1
8
1
9
1
12
Answer: Option
Explanation:

In two throws of a dice, n(S) = (6 x 6) = 36.

Let E = event of getting a sum ={(3, 6), (4, 5), (5, 4), (6, 3)}.

P(E) = n(E) = 4 = 1 .
n(S) 36 9


5.
Three unbiased coins are tossed. What is the probability of getting at most two heads?
3
4
1
4
3
8
7
8
Answer: Option
Explanation:

Here S = {TTT, TTH, THT, HTT, THH, HTH, HHT, HHH}

Let E = event of getting at most two heads.

Then E = {TTT, TTH, THT, HTT, THH, HTH, HHT}.

P(E) = n(E) = 7 .
n(S) 8